Pegasus Boeing 737-800 overuns runway at Istanbul and breaks up.

Pegasus airlines, a Turkish low cost carrier, has had a third runway excursion with fatal results.

This incident is shocking on several levels. The most obvious is that one airline can have three runway overruns or excursions at all and secondly; what is the role of the Turkish aviation authorities in this latest crash? Was there no close oversight of this company after its previous terrible record?

From what is known the day after the event it is clear that this was a totally avoidable crash. I will not call it an accident as it seems to have been created by the crew decisions so far as we can see and it points to a serious problem with the safety culture in this airline.

Amid all the talk of bad weather and strong winds it is important to look at the process that is normal in such weather.

Both an individual airline as well as the aircraft manufacturer will set limits and define procedures to be followed to cover pretty much every situation. Pilots in professionally run airlines are trained, tested and monitored constantly to ensure these rules are followed. In the view of many professional pilots it is felt that had correct measures been employed here this would not have happened; so what are these measures?

There will be a maximum cross wind permitted for landing as well as a maximum tailwind for any aircraft; usually provided by the manufacturer. It is a requirement that before takeoff, and or landing, the crew must calculate and assess the takeoff or landing performance required in order to assess what is possible and if it is not possible within those rules, then what the plan is.

In this case the runway was wet as there were showers – some heavy – in the area but critically, the wind was from the West, strong and gusting. The runway in use, and that which the crew attempted to land on, pointed to the North East (060 degrees) and so there was both a cross and tailwind component; it is the tail element that seems to have been a major factor. Additionally, the wind direction seems to have shifted further towards a tailwind.

The reported gusts were well outside the permitted tail component but there is more than simply that. From the data available it seems that the aircraft was high, fast and touched down a long way past the touchdown zone.

So far past the correct point in fact, that it is suggested that it could be as much as two thirds of the way down the runway. In such circumstances it is almost certain that the aircraft will be unable to stop before the runway end.

The correct procedure when that situation began to develop, is to go around and either request a different runway or divert to another destination where the weather is within published limits. To press on when it is looking questionable or, “give it a go,” is not professional conduct and should never be done.

We cannot know at this point what caused the crew to take the decision that they did but it is clear that it was not the right one. Commercial aircraft can reach the runway threshold and still go around if the crew are not happy with the stability of the approach or if the landing looks out of shape.

No doubt more information will emerge and I will update this page as more data is acquired. Sadly it seems that so far three people have died as a result of the crash, the condition of the remaining people us unknown at this point.

Update 12.2.20:

From the publically available data, it appears that the aircraft was both above and below the correct approach slope during approach and ended up high, as well as fast, and with a considerable tail wind. Given all these factors it does not appear to have been a stable approach and should have been abandoned – a go around – and another approach made in better conditions after reassessment of the situation, such as a change or runway, which I understand was intended by air traffic control.